Coastal weathering and erosion

Coastal weathering and erosionWeathering is the breakdown of rocks where they are. Erosion is when the rocks arebroken down and carried away by something.Mechanical WeatheringMechanical weathering is the breakdown of rock without changing its chemicalcomposition. There's one main type of mechanical weathering that affects coasts-freeze thaw weathering; It happens when the temperature alternates above and below 0oC Water gets into cracks in rocks When the water freezes it expands, which puts pressure on the rock When the water thaws it contracts, which releases the pressure on the rock Repeated freezing and thawing widens the cracks and causes the rock to break upChemical WeatheringChemical weathering is the breakdown of rock by changing its chemical composition.Carbonation weathering is a type of chemical weathering that happens in warm and wetconditions: Rain water has carbon dioxide dissolved in it, which makes it a weak carbonic acid Carbonic acid reacts with rock that contains calcium carbonate e.g. carboniferous limestone, so the rocks are dissolved by the rainwater